Matt, I can only see one kind of fully-featured micro USB cable at Monoprice, which is the same as the two I bought previously. Available in different lengths, here's a link to a short one:

http://www.monoprice.com/products/produc...rmat=4#feedback

If yours isn't working with the kindle then it might be an insertion problem or other manufacturing defect. Monoprice does ship bad cables every now and then. Sometimes a handful of them as was the case with some HDMI cables I bought.